Switching power supplies are well known. A switching power supply has a primary side and a secondary side, wherein the secondary side is inductively coupled to the primary side to produce at least one voltage. The primary side operates from line voltage. A primary side controller controls the primary side to provide a controlled output voltage. Known designs include those wherein a secondary side controller provides feedback control (of appropriate gain and phase for the particular switching power supply) of one of the secondary side voltages of the secondary side to the primary side controller to maintain stability of that voltage under varying load conditions.
Switching power supplies are used to run power-supply-using devices. Power-supply-using devices include, without limitation, printers (without a power supply), such as ink jet printers having a printer controller, having a print head, and having a print head carriage motor and one or more paper feed motors. The printer controller controls the operation of the motors and the print head to eject ink onto the paper. The device and the power supply together may be called a device-and-power-supply assembly.
Certain devices, such as computer monitors and copiers are known to operate in reduced power modes when the device is idle. Certain devices, such as ink jet printers, are known to operate with external (i.e., external to the printer housing) power supplies and with internal (i.e., internal to the printer housing) power supplies.
What is needed is one or more of an improved switching power supply, an improved method for operating a switching power supply, and an improved device-and-power-supply assembly.